The invention relates generally to traps in drain plumbing and more particularly to a readily cleanable trap which functions not only as a gas trap in a drain line, but also a filter as well as an air-water separator and numerous other filtering functions.
Various styles of plumbing traps which block flow of sewer gas back-flowing through a drain line have been available since the inception of indoor plumbing. The commonly coniiguredp-trap or S-trap have been utilized since the last century. A trap which provides a removable cup is typified by U.S. Pat. No. 1,210,201. Other types of cleanable traps are shown in U.S. Pat. Nos. 2,742,101, 3,994,031, 2,170,390 and 919,701.